Parts for Detroit Diesel 471 Non-Turbo - (4 Valve Head Type)

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Detroit Diesel 471 Non-Turbo 4-Valve Engine Specifications & Applications

Overview of the Detroit Diesel 471 Non-Turbo 4-Valve Engine

The Detroit Diesel 471 Non-Turbo 4-Valve engine is a variant of the legendary 71 Series lineup. Built for reliability, durability, and field serviceability, this model features a naturally aspirated design paired with a 4-valve cylinder head, offering improved airflow and efficiency.

This engine is a mechanical marvel appreciated by operators in marine, generator, and industrial settings. With no turbocharging, fewer electronics, and a proven two-stroke platform, the 471 4-valve engine is favored in long-service marine vessels, military support equipment, classic diesel trucks, and backup power units. Its 4-valve head delivers better breathing—leading to more complete combustion and slightly improved fuel economy and performance—without compromising on the simplicity that the 471 series is known for.

At Diesel Pro Power, we proudly support this engine with premium aftermarket parts that outperform or match OEM standards. With quick shipping, expert support, and a full line of service kits, rebuild parts, and replacements, we’re here to ensure your 471 4-valve engine keeps running strong.

Key Specifications of the Detroit Diesel 471 4-Valve Non-Turbo Engine

Engine Configuration

Model: Detroit Diesel 471 (4-cylinder)
Series: 71 Series two-stroke engine
Valvetrain: 4 valves per cylinder
Number of Cylinders: 4 (inline configuration)
Aspiration: Naturally aspirated (non-turbo)
Fuel System: Mechanical unit injectors (timed and pressure-actuated)
Cycle: Two-stroke diesel
Firing Order: 1-3-4-2
Compression Ratio: ~17.0:1
Rated Power Output: Approx. 130–160 HP @ 1,800–2,100 RPM (depending on governor settings and injector size)
GovernDimensions or Options: Mechanical (limiting and variable speed)

Internal & Capacities

Bore: 4.25 inches (108 mm)
Stroke: 5.00 inches (127 mm)
Displacement: 284 cubic inches (4.65 liters)
Oil Capacity (with filter): ~7.5 gallons (28.4 liters)
Cooling System Capacity: ~6.5 gallons (24.6 liters)
Oil Pressure (at operating RPM): 40 – 60 PSI
Operating Temperature Range: 170°F – 195°F
Maximum Allowable Coolant Temp: 200°F
Idle RPM Range: 500 – 600 RPM
Rated RPM Range: 1,800 – 2,100 RPM

Engine Weight and Dimensions

Dry Weight (Base Engine): ~1,650 lbs (748 kg)
Length: ~52 inches (132 cm)
Width: ~29 inches (74 cm)
Height: ~39 inches (99 cm)

What’s the Difference Between 2-Valve and 4-Valve 471 Engines?

The main difference lies in the cylinder head configuration:

2-Valve Head: One intake and one exhaust valve per cylinder. Standard breathing capacity.
4-Valve Head: Two intake and two exhaust valves per cylinder. Enhanced air intake and exhaust flow.

Benefits of 4-Valve Configuration

Improved Airflow: Increased volumetric efficiency for better combustion and marginally higher horsepower.
Lower Emissions: Cleaner exhaust due to more complete fuel burn.
Better Performance at Higher RPMs: Especially useful in marine vessels or equipment under constant load.
Greater Efficiency: Slight improvement in fuel economy and throttle response.

Marine Applications of the Detroit Diesel 471 4-Valve Engine

This engine variant has powered countless vessels across oceans, harbors, and rivers for decades. It's especially valued in environments where dependability and mechanical simplicity are more important than digital controls or high-horsepower performance.

Recreational Marine Use

Vintage Yachts & Trawlers: A favorite among restorers of 1960s–1980s long-range trawlers and live-aboard boats.
Personal Fishing Vessels: Valued for simplicity and cold-start reliability in seasonal sportfishing boats.
Retrofit Marine Projects: Often used in sailboats or smaller cruisers as a backup or main propulsion engine.

Commercial Marine Use

Shrimp Boats & Crabbers: Especially in the Gulf of Mexico and Alaska.
Work Barges & Dredges: Trusted in high-torque, low-speed workboats.
Ferry Vessels: Deployed in older passenger ferries where engine rooms have tight space constraints.
Tugboats: Used in harbor tugboats or assist vessels in regional ports.

Industrial Applications of the 471 Non-Turbo 4-Valve Engine

Outside marine service, this engine has seen widespread industrial deployment:

Generators: Common in standby and primary power units from 40–80 kW.
Hydraulic Pumps & Water Movers: Used in irrigation, flood control, and mining operations.
Construction Equipment: Formerly installed in cranes, rock crushers, and earthmoving machines.
Drilling Rigs: Found in well-servicing units and oilfield equipment.
Portable Compressors & Air Units: Especially in military or government setups.

Military Applications of the 471 4-Valve

The U.S. Armed Forces and several NATO militaries have relied on the 471 family for decades:

Landing Craft & Amphibious Assault Boats
Transportable Generator Sets
Tank Recovery Vehicles
Fuel Transfer Systems

Its 4-valve head variant is preferred in high-output environments where constant load and air efficiency are vital.

Aftermarket Support for the 471 4-Valve Engine

At Diesel Pro Power, we recognize that most 471 engines still in service today are decades old. OEM parts are no longer produced in volume, and many suppliers no longer carry complete kits for the 4-valve variant. That's where we step in.

We provide a full range of aftermarket parts for this engine that meet or exceed OEM tolerances, including: